Motor fuel process



. Sept. 20, 1932. .J. J. LAWTON MOTOR FUEL PROCESS Filed Oct. 24, 1928 J 055% J- LA W70 INVENTOR 14; ATTORNEY Patented Sept. 20, 1932 UNITED JOSEPH J.I.Awro1v,orsYimcUsE, New Yomr, ASSIGNOR 'r'o sEMEr soLvAv comrnmg oryrmw Yoax, N. Y., A coarorm'rron on NEW YORK Moron FUEL rnocnss Application filed oetote'r'ai, 1928. Serial in, 314,631,

The present invention relates'to an improved method for refining crude coke oven light oil obtained by .the destructive distillation of coal and particularly to an im- 5i proved method for the production'from such oil of a motor fuel adapted for use ininternal combustion engines, and to the improved fuel thus produced. i

In the production of motor fuel fromilight oil as carried out heretofore, it has been the practice to submitthe oil or the particular fraction thereof which is useful as a motor fuel to a preliminary purification treatment x with sulfuric acid. This purification has been 1 deemed necessary to remove from the oil certain constituents such as unsaturated hydrocarbons considered as'undesirable in amotor' fuel. In carrying out this purification treatment it is'necessary to agitate theoil thor- 2 oughly with sulfuric acid, separate the resultant acid sludge,andthenneutralize the oil by treatment with caustic, The cost of the acid, caustic,agitators, etc. represents a substantial part of the total outlay necessary in the production of a motorfuel'a'nd under some-conditions such as those prevailing in small plants'where a relatively'limited quantity of crude light oil is produced, the expense incident to such purification operations renders the process of refining the light oil into motor fuel commercially prohibitive. The principal object vof this invention. is

the production directly from crude coke oven light oil of a fractional distillate which is crude oil undesirablein a motor fuelis va-j porized and separately collected and c011- essary After the separation of this low boil} densed. I have found that by slowly distilling 'ofl' a'low boiling fraction amounting-to about 10-15%by volume of the crudebil the low boiling impurities of the crude oil objectionable in a motor fuel, including sulfur impurities removable by a distillation operation, may be satisfactorily removed therefrom to such an extent'as to render purifying the motor fuel fraction with sulfuric acid unnece' ing distillate, the heating of the oil charge is continued and a distillate produced having characteristics which adapt itfor use as a motor fuel without further purification. 'In; the production of this fraction, therateof distillation is preferably regulated so that only small quantities of toluol arepresent'in the distillate, the toluol content ofthe total distillatein' general, being not in excess of about 2% and the" dry or end point of the distillate,ordinarily;*being about 95-100 C. Heating of the oil charge is then preferably I continued until a sample of the residuewhen testedhas a first drop point of about G. The fraction obtained by'this distillation is preferably combined with "the low boiling fraction initially obtained and the resultant product may be marketed'as such or purified by treatment with sulfuric acid in the usual manner and separated into pure-products by so distillation. The amount of 'sul-furicfacid needed for the purification of these combined fractions is much less than that required for the'purification of a corresponding amount of crude oil. The distillation residue may be disposed of as coal tar oil. Y

Referring to the accompanying drawing which illustrates diagrammatically a suitable fo'rm ofapparatus Zfor practising the invention, a still 1 is provided having a conduit 2 for the introduction of crude oil thereto and equipped with both-indirect heating means, steam coil 3, and direct heating means, steam pipe 4, having aperture stherein for the introduction of steam into the d1s-' W tillation mass. Extending from the still is r a stand pipe 5 andconnec'te'd in parallel theree .withisa suitable form of distilling column 6 :equippedwith'any usual form of distrlla tion rings or'plates. Valves8, 9 and 10 di-I 1 root the vapors evolved from thestill through The upper end of the distilling column 6 ispreferably provided with a water cooled reflux condenser of a conventionalv type for controlling the rate. of distillation? Stand pipe 5 leads to-condenser 11 which is connected to a separatory vessel 12 for separat an '-wa:ter resent? in the condensate;

tanks 13 for separately collecting the various fractional condensates.

The method of operating the apparatus will be apparent fromthe foregoing'and'the following illustrative: enample of the appli; cation oftheinvention to a crude cokeioven havingacombined-.benzoll? content, i e. benzene toluol, etc.,fof about 9%.

- Approximately 8000v gallons of this: crude oilare charged intothe stilll and distilla-j' tion initiated by paSS P g of steam through coil 3.. Valve 8.-is closed and-valves? and 10,

i are open so thatthe evolved vapors-passinto distilling .6. Vap o-rs are withdrawn:

from the top/of reflux condenser through pipes 9 and condensedin. condenser 13,1 andthe condensate collected inone of the collecting tanks '13. a The distillation ;;-should he carried out at a slow rate so that; substantiallyallgof the: low boiling constituentsune v desirable in, a motor fuel. and relatively free from the desired motor fuel fraction ane dis tilled oflg; as for example aboutlfiQ- gallons on about 2% per hour, control; of the ;rate;ofdistillation beingh ad by'adjustment of re flux condenser" 7 and steamcoil V The rate of; distillation may be varied somewhat according to: the character of the crude oil, the quality of the motor fuel desired, and similar conditions However, the. optimum rate for any given-set of conditions may be readily ascertained by submitting the product, particularly the subsequently formed motor fuel fractiom: to the usual tests.- The distillation is continued until the distillate tests; about 713: 'C-. (first. drop and its volume. amounts tOPRBOlIB-925 gallons, i;. a, an amount equivalentxto about 12%; of the oil charged. :The; wparation ofaa. low boiling; fraction having a volume of about 10-15% at asuitable'rate o of distillation as indicated, ordinarilysuflines; to remove from the crude oil substane tially all of its low boiling constituents untion continued until the resulting distillate a; volume. of-about 40 '50%-based'- upon the volume of crude oil charged, e. g., about 3800 gallons, and an'end or dry point corresponding to that of the desired motor fuel,

for example, about 95-100 C. This fraction is likewise condensed in condenser 11 but is separately collected and. disposed of directly Themoter fuel provided by this invention Connected to theiiseparato-ry vessel" are two-l may be distinguished from the heretofore known types of'motor fuel derived from coke ovenl-i'ght-oil since the absence of any treat- .ment with sulfuric acid in its production imparts certain" distinguishing characteristics thereto. For instance, the motor fuel pro ducedaccording to my invention has an acidwash color above normal, being above 145 on the, standard, test. scale known as ,Barrett Colorimetric. Scale, (of; Jou naljof Indus trial 'and Engineering Chemistry for 1918',- page-1 006):while other motor fuels also produced from crude coke oven-light oilbut-by "a process involving their purification with SlllfllllC'ifiQld havel-an acid wash color below While n process satisfactorily removes low boiling'i-Inpurities which are undesirable 1n a motorffuel, for example giving rise to adiscolored product' onstanding, i t does not remove all the unsaturated hydrocarbons as is the; case when the acid purification treatmenthereinabove referred tois used; Au-

thoritijes now :hold that certain of these unsaturated bodies ofitheol-efi'ne type arenot only not u ndesi-rablejfin a motor fuel .but are; beneficialv in that a they impart anti-knock" properties 'to the fuel. Accordingly not only does imyz process 'remov'e undesirable materials for whichit has been necessaryhereto fore to use the expensive I acidtreatment, but. materials heretoforeremoved by such treat, ment and which, are not only noninjurious butfbeneficial, are caused to remain,.thereby giving anew and improved motor benzolfuel.

After, the separation of the motor: fuel fraction valves 9 and 10; are closed and valve 8 openedsothat the vapors pass directly through stand pipe 5 over into condenser 11 7 and distillation of the crude oil" is continued preferably with the use of direct steam sup plied} through pipe 4;; Water present in the condensate isseparated in the'separatory vessel 12,. and the; distillation continued until a sample of the-residue remaining .in still 1 has a first drop point ofaboutrl C. and the total fraction "from this; distillation has a volume of about 30-40% 'of; the crude oil charged, for-example, about 2300 gallons.

, This fraction comprises practically all the toluol contentlof'the crudevoil, and the high boiling constituents commonly designated as the fsolventfffraction; fThis toluol-solvent fraction;- is"; preferably combined with the'low boiling fraction initially obtained giving a instance it has been found that the acid re-' quired is much less than that required according to the usual practice of submitting all the crude oil to theacid treatment and then distilling for the production of the motor fueland other fractions.

By the term crude coke oven light oil, used in the claims, is meant light oil which has not been washed with sulphuric acid or otherwise purified.

' What is claimed is: p

1. The process of producing motor fuel from crude coke oven light oil which comprises slowly distilling the crude oil whereby to separate a low boiling fraction having a volumeof about 10-15 based upon the crude oil and containing lowboiling constituents undesirable in a motor fuel, condensing and separately collecting said low boiling fraction, further slowly distilling the crude oil and separately collecting the distillate until i it has a volume of about 4050% based upon the crude oil, whereby a fractional distillate is produced suitable for utilization as a motor fuel without further purification.

2; The process of producing motor fuel from crude coke oven light oil which comprises slowly distilling crude oil whereby to separate a low-boiling fraction having a volume of about 10 to 15 per cent based upon the crude oil and containing low-boiling constituents undesirable in a motor fuel, condensing and separately collecting saidlowboiling fraction, further slowly distilling the crude oil and separately collecting the distillate until small quantities of toluol occur therein whereby a fractional distillate is produced containing not more than about 2 per cent of toluol and suitable for utilization as a motor fuel without further purification, continuing the distillation to separate a toluol fraction, and condensing and combining said toluol fraction with the low-boiling fraction initi ally produced.

In witness whereof I hereto setmy hand.

JOSEPH J. LAWTON. 

